It looks to me like SDM is not capable of adding a secondary IP address to an interface. Am I missing something? If I add a secondary IP address at the CLI I presume that SDM would become unaware of the secondary IP - correct?
We can able to configure through CLI only
Follow this steps to configure the secondary network on the router using CLI.
ip address 10.227.220.1 255.255.255.0 secondary
GRE/IPSec enhancements-You can configure a secondary GRE tunnel, and add routing information to the GRE/IPSec configuration.